创伤后应激障碍（PTSD）的生物学研究概述

创伤后应激障碍（posttraumatic stress disorder,PTSD）是灾害后精神及行为障碍的一种重要表现形式,具有发病率及患病率高、病程长、疗效差等特点,严重影响了临床救治。对于创伤后应激障碍发病机制及其防治的研究日益受到关注。致力于PTSD研究的研究者,从行为学、神经内分泌等宏观研究,到形态学、细胞分子生物学等功能研究,再到临床实验研究,做了大量的工作,得到了许多具有实际指导意义的结果。本文针对国内外研究者近年来在这方面的研究现状进行综述,从宏观上为PTSD后续的研究提供一些循证的证据。     

Gelatin degradation assay reveals MMP-9 inhibitors and function of O-glycosylated domain

AIM: To establish a novel, sensitive and high-throughput gelatinolytic assay to define new inhibitors and compare domain deletion mutants of gelatinase B/matrix metalloproteinase (MMP)-9. METHODS: Fluorogenic Dye-quenched (DQ)TM-gelatin was used as a substrate and biochemical parameters (substrate and enzyme concentrations, DMSO solvent concentrations) were optimized to establish a highthroughput assay system. Various small-sized libraries (ChemDiv, InterBioScreen and ChemBridge) of hetero-cyclic, drug-like substances were tested and compared with prototypic inhibitors. RESULTS: First, we designed a test system with gelatin as a natural substrate. Second, the assay was validated by selecting a novel pyrimidine-2,4,6-trione (barbitu- rate) inhibitor. Third, and in line with present structural data on collagenolysis, it was found that deletion of the O-glycosylated region significantly decreased gelatinolytic activity (kcat/kM ± 40% less than full-length MMP-9). CONCLUSION: The DQTM-gelatin assay is useful in high-throughput drug screening and exosite targeting. We demonstrate that flexibility between the catalytic and hemopexin domain is functionally critical for gelatinolysis.     

药用植物款冬花芽分化过程观察

实验以不同生长发育阶段的款冬花序芽突起为材料,通过制作石蜡切片,在显微镜下观察款冬花序芽分化各阶段的形态特征。结果表明:款冬花序芽从7月上旬开始花序(盘)分化至十月初小花胚珠分化完成,分化时期可分为分化前期、花盘形成期、花原基分化期、中央花(筒状)花瓣原基分化期、中央花雄蕊原基分化期、中央花雌蕊原基分化期、边缘花(舌状)花瓣原基分化期、边缘花雌蕊原基分化期、中央花花粉分化形成期、子房胚珠分化期共10个时期,阐明了款冬花序芽分化各时期与生长时间的关系。     

Cytological analysis and genetic control of rice anther development

Microsporogenesis and male gametogenesis are essential for the alternating life cycle of flowering plants between diploid sporophyte and haploid gametophyte generations.Rice (Oryza sativa) is the world's major staple food,and manipulation of pollen fertility is particularly important for the demands to increase rice grain yield.Towards a better understanding of the mechanisms controlling rice male reproductive development,we describe here the cytological changes of anther development through 14 stages,including cell division,differentiation and degeneration of somatic tissues consisting of four concentric cell layers surrounding and supporting reproductive cells as they form mature pollen grains through meiosis and mitosis.Furthermore,we compare the morphological difference of anthers and pollen grains in both monocot rice and eudicot Arabidopsis thaliana.Additionally,we describe the key genes identified to date critical for rice anther development and pollen formation.     

There is no trade-off between speed and force in a dynamic lever system

Lever systems within a skeleton transmit force with a capacity determined by the mechanical advantage, A. A is the distance from input force to a joint, divided by the distance from the joint to the output force. A lever with a relatively high A in static equilibrium has a great capacity to generate force but moves a load over a small distance. Therefore, the geometry of a skeletal lever presents a trade-off between force and speed under quasi-static conditions. The present study considers skeletal dynamics that do not assume static equilibrium by modelling kicking by a locust leg, which is powered by stored elastic energy. This model predicts that the output force of this lever is proportional to A, but its maximum speed is independent of A. Therefore, no trade-off between force and velocity exists in a lever system with spring-mass dynamics. This demonstrates that the motion of a skeleton depends on the major forces that govern its dynamics and cannot be inferred from skeletal geometry alone.     

Aphis (Hemiptera: Aphididae) species groups found in the Midwestern United States and their contribution to the phylogenetic knowledge of the genus

A phylogeny of the genus Aphis Linnaeus, 1 758 was built primarily from specimens collected in the Midwest of the United States. A data matrix was constructed with 68 species and 41 morphological characters with respective character states of alate and apterous viviparous females. Dendrogram topologies of analyses performed using UPGMA (Unweighted Pair Group Method with Arithmetic Mean), Maximum Parsimony and Bayesian analysis of Cytochrome Oxidase I, Elongation Factor 1‐α and primary endosymbiont Buchnera aphidicola 16S sequences were not congruent. Bayesian analysis strongly supported most terminal nodes of the phylogenetic trees. The phylogeny was strongly supported by EF1‐α, and analysis of COI and EF1‐α molecular data combined with morphological characters. It was not supported by single analysis of COI or Buchnera aphidicola 16S. Results from the Bayesian phylogeny show 4 main species groups: asclepiadis, fabae, gossypii, and middletonii. Results place Aphis and species of the genera Protaphis Börner, 1952, Toxoptera Koch, 1856 and Xerobion Nevsky, 1928 in a monophyletic clade. Morphological characters support this monophyly as well. The phylogeny shows that the monophyletic clade of the North American middletonii species group belong to the genus Protaphis: P. debilicornis (Gillette & Palmer, 1929 ), comb. nov., P. echinaceae (Lagos and Voegtlin, 2009 ), comb. nov., and P. middletonii (Thomas, 1879 ). The genus Toxoptera should be considered a subgenus of Aphis (stat. nov.). The analysis also indicates that the current genus Iowana Frison, 1954 should be considered a subgenus of Aphis (stat. nov.).     

Four new species of the Australian Pamborus Latreille (Coleoptera, Carabidae) carabid beetles

Abstract  Based on an examination of the type specimens of all the known species of the genus Pamborus Latrielle (Coleoptera, Carabidae) four new Australian species are recognised and are described as: P. euopacus sp. n., P. moorei sp. n., P. monteithi sp. n and P. cooloolensis sp. n. In addition, Pamborus viridis Gory, P. opacus Géhin and P. subtropicus Darlington are also redescribed based on the type material and lectotypes are designated for the first two species.     

Developmental differences in visceral morphology of megophryine pelobatid tadpoles in relation to their body form and mode of life

Tadpoles face severe packing constraints on viscera within the pleuro-peritoneal cavity because of their extremely short torsos—a feature they share with adult anurans—and the concomitant need for relatively slender torsos for efficient locomotion. We examined the effects of differences in body form and habits on the size, shape and development of viscera in three kinds of sympatric, stream-associated pelobatid tadpoles. Leptobrachium montanumlarvae are generalized, wide, deep-bodied tadpoles. Larval Leptolalax gracilis are very slender and live in the crevices between rocks on the bottom of riffles. Larval Megophrys nasuta are intermediate between the other two in body form, and live with L. montanum in a variety of microhabitats but feed at the surface film. In all three species, liver, gall bladder, arid kidneys begin development early and grow isometrically throughout larval life. The gut and pancreas have a growth spurt shortly after hatching, then grow at a constant rate until near metamorphosis when both shrink drastically. The spleen grows at a slower rate than the body throughout the larval period. Lungs do not appear in L. gracilis until the tadpole approaches metamorphosis, which accords with its benthic habits, whereas they grow throughout the larval period in L. montanum and M. nasuta. In M. nasuta, however, the lungs are unusually wide anteriorly; this shifts buoyancy forward and facilitates the head-up feeding posture characteristic of that species. Gonads appear early in L. montanum and L. gracilis, but not until near metamorphosis in M. nasuta. We suggest that accelerated gonadal development in tadpoles characterizes species that metamorphose close to their size at first reproduction. Leptobrachium montanum, with the bulkiest body and most generalized habits, has relatively and absolutely the largest gut, liver (x of combined gut and liver volume = 24%, of total volume), and kidneys. Leptolalax gracilis, the most slender tadpole, has relatively the smallest combined gut and liver volume (x = 10% of total volume). Other premetamorphic differences among the species were observed in gut coiling, liver, pancreas and kidney shape and left/right asymmetry of urogenital organs. The major interspecific differences we observed in the size, shape, and developmental patterns of viscera in tadpoles are clearly related to interspecific differences in torso shape, microhabitat distribution and mode of feeding.     

Comparative morphology of mandibular structures in lycid larvae and its phylogenetic implications (Polyphaga, Hexapoda)

The morphology of the larval mandibular structures of the family Lycidae (Polyphaga) is characterized by facultative dicondyly, posterior articulation with long mandibular rods, lateral location of the anterior condyle and its articulation with a paired non‐cranial structure. It is compared to that of Eucrustacea, Chilopoda, Entognatha, Microcoryphia and Zygentoma and found to be more reminiscent of the Entognatha. The phylogenetic implications of this conclusion are discussed, with the Pterygota and Dicondylia hypothesized to be non‐monophyletic.